Paper Title
CONCRETE-FILLED STEEL TUBE COLUMNS OF DIFFERENT CROSS-SECTIONAL SHAPES UNDER AXIAL COMPRESSION

Abstract
Abstract: Specially shaped CFST concrete-filled steel tube composite column structures enhance architectural space compared with traditional ones. However most codes dimension and calculate the capacity of CFST based on thickness, height and strength of steel and concrete with ordinary shapes. The shape of cross-section is the key parameter in this study in order to have the effect on the concrete confinement, the strength of the steel walls of the CFST and on the fundamental modes of deformation. CFST test specimens in ordinary shapes (squares, rectangles, triangles, hexagons and circles) and in special forms inspired by these ordinary ones. In this experimental study, 23 CFST columns were produced to improve and understand the mechanical behaviour of columns in compression. Keywords - Axial compression, Concrete filled steel tube CFST, Section shape effect, Confinement, Local buckling, Deformation modes, Experimental, Perimeter.